Patents by Inventor Steven P. Denbaars

Steven P. Denbaars has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20180013035
    Abstract: A method for growth and fabrication of semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices, comprising identifying desired material properties for a particular device application, selecting a semipolar growth orientation based on the desired material properties, selecting a suitable substrate for growth of the selected semipolar growth orientation, growing a planar semipolar (Ga,Al,In,B)N template or nucleation layer on the substrate, and growing the semipolar (Ga,Al,In,B)N thin films, heterostructures or devices on the planar semipolar (Ga,Al,In,B)N template or nucleation layer. The method results in a large area of the semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices being parallel to the substrate surface.
    Type: Application
    Filed: September 7, 2017
    Publication date: January 11, 2018
    Applicants: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA, Japan Science and Technology Agency
    Inventors: Robert M. Farrell, JR., Troy J. Baker, Arpan Chakraborty, Benjamin A. Haskell, P. Morgan Pattison, Rajat Sharma, Umesh K. Mishra, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Patent number: 9859464
    Abstract: This invention is related to LED Light Extraction for optoelectronic applications. More particularly the invention relates to (Al, Ga, In)N combined with optimized optics and phosphor layer for highly efficient (Al, Ga, In)N based light emitting diodes applications, and its fabrication method. A further extension is the general combination of a shaped high refractive index light extraction material combined with a shaped optical element.
    Type: Grant
    Filed: December 23, 2015
    Date of Patent: January 2, 2018
    Assignee: The Regents of the University of California
    Inventors: Natalie Fellows DeMille, Steven P. DenBaars, Shuji Nakamura
  • Patent number: 9828695
    Abstract: A nonpolar III-nitride film grown on a miscut angle of a substrate, in order to suppress the surface undulations, is provided. The surface morphology of the film is improved with a miscut angle towards an a-axis direction comprising a 0.15° or greater miscut angle towards the a-axis direction and a less than 30° miscut angle towards the a-axis direction.
    Type: Grant
    Filed: April 20, 2016
    Date of Patent: November 28, 2017
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Asako Hirai, Zhongyuan Jia, Makoto Saito, Hisashi Yamada, Kenji Iso, Steven P. DenBaars, Shuji Nakamura, James S. Speck
  • Publication number: 20170327969
    Abstract: A nonpolar III-nitride film grown on a miscut angle of a substrate. The miscut angle towards the <000-1> direction is 0.75° or greater miscut and less than 27° miscut towards the <000-1> direction. Surface undulations are suppressed and may comprise faceted pyramids. A device fabricated using the film is also disclosed. A nonpolar III-nitride film having a smooth surface morphology fabricated using a method comprising selecting a miscut angle of a substrate upon which the nonpolar III-nitride films are grown in order to suppress surface undulations of the nonpolar III-nitride films. A nonpolar III-nitride-based device grown on a film having a smooth surface morphology grown on a miscut angle of a substrate which the nonpolar III-nitride films are grown. The miscut angle may also be selected to achieve long wavelength light emission from the nonpolar film.
    Type: Application
    Filed: May 26, 2017
    Publication date: November 16, 2017
    Applicant: The Regents of the University of California
    Inventors: Kenji Iso, Hisashi Yamada, Makoto Saito, Asako Hirai, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Patent number: 9793435
    Abstract: A method for growth and fabrication of semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices, comprising identifying desired material properties for a particular device application, selecting a semipolar growth orientation based on the desired material properties, selecting a suitable substrate for growth of the selected semipolar growth orientation, growing a planar semipolar (Ga,Al,In,B)N template or nucleation layer on the substrate, and growing the semipolar (Ga,Al,In,B)N thin films, heterostructures or devices on the planar semipolar (Ga,Al,In,B)N template or nucleation layer. The method results in a large area of the semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices being parallel to the substrate surface.
    Type: Grant
    Filed: November 30, 2015
    Date of Patent: October 17, 2017
    Assignees: The Regents of the University of California, Japan Science and Technology Agency
    Inventors: Robert M. Farrell, Jr., Troy J. Baker, Arpan Chakraborty, Benjamin A. Haskell, P. Morgan Pattison, Rajat Sharma, Umesh K. Mishra, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Patent number: 9773704
    Abstract: A method for the reuse of gallium nitride (GaN) epitaxial substrates uses band-gap-selective photoelectrochemical (PEC) etching to remove one or more epitaxial layers from bulk or free-standing GaN substrates without damaging the substrate, allowing the substrate to be reused for further growth of additional epitaxial layers. The method facilitates a significant cost reduction in device production by permitting the reuse of expensive bulk or free-standing GaN substrates.
    Type: Grant
    Filed: June 22, 2016
    Date of Patent: September 26, 2017
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Casey O. Holder, Daniel F. Feezell, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20170236807
    Abstract: III-V micro light-emitting diodes (LEDs) are fabricated using a photoelectrochemical (PEC) etch. A sacrificial layer and III-V device layers are epitaxially grown on a host substrate, wherein the III-V device layers are patterned to form the micro-LEDs. The sacrificial layer is removed by a photoelectrochemical (PEC) etch, so as to fully or partially separate the micro-LEDs from the substrate, before or after the micro-LEDs are bonded to a submount or intermediate substrate. The micro-LEDs may be bonded to a submount with a polymer film deposited thereon, wherein the polymer film with the micro-LEDs is subsequently delaminated from the submount. Alternatively, the intermediate substrate may be a transfer medium, wherein the micro-LEDs are separated from the host substrate by mechanical fracturing, and then bonded to a second substrate, after which the intermediate substrate is removed, wherein a third substrate may be bonded to exposed surfaces of the transferred micro-LEDs.
    Type: Application
    Filed: April 28, 2017
    Publication date: August 17, 2017
    Applicant: The Regents of the University of California
    Inventors: David Hwang, Nathan G. Young, Ben Yonkee, Burhan K. Saifaddin, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Patent number: 9653655
    Abstract: A method for fabricating a Light Emitting Diode (LED) with increased light extraction efficiency, comprising providing a III-Nitride based LED structure comprising a light emitting active layer between a p-type layer and an n-type layer; growing a Zinc Oxide (ZnO) layer epitaxially on the p-type layer by submerging a surface of the p-type layer in a low temperature aqueous solution, wherein the ZnO layer is a transparent current spreading layer; and depositing a p-type contact on the ZnO layer. The increase in efficiency may be more than 93% with very little or no increase in cost.
    Type: Grant
    Filed: November 3, 2010
    Date of Patent: May 16, 2017
    Assignee: The Regents of the University of California
    Inventors: Daniel B. Thompson, Jacob J. Richardson, Steven P. DenBaars, Jin Hyeok Kim, MaryAnn E. Lange
  • Publication number: 20170130910
    Abstract: A high-power, high-brightness lighting system for large venue lighting, which includes a laser diode as the excitation source and one or more phosphor materials placed at a remote distance from the laser source. The invention offers a lighting system with the advantages of high brightness, high efficiency, high luminous efficacy, long lifetimes, quick turn-on times, suitable color properties, environmental sustainability, and easy maintenance, which may allow for smart and flexible control over large area lighting systems with resulting savings in operating and maintenance costs.
    Type: Application
    Filed: January 23, 2017
    Publication date: May 11, 2017
    Applicant: The Regents of the University of California
    Inventors: Kristin A. Denault, Steven P. DenBaars, Ram Seshadri
  • Patent number: 9640947
    Abstract: A III-Nitride based Vertical Cavity Surface Emitting Laser (VCSEL), wherein a cavity length of the VCSEL is controlled by etching.
    Type: Grant
    Filed: August 6, 2015
    Date of Patent: May 2, 2017
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Casey O. Holder, Daniel F. Feezell, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Patent number: 9611987
    Abstract: A white light source employing a III-nitride based laser diode pumping one or more phosphors. The III-nitride laser diode emits light in a first wavelength range that is down-converted to light in a second wavelength range by the phosphors, wherein the light in the first wavelength range is combined with the light in the second wavelength range to create highly directional white light. The light in the first wavelength range comprises ultraviolet, violet, blue and/or green light, while the light in the second wavelength range comprises green, yellow and/or red light.
    Type: Grant
    Filed: October 29, 2013
    Date of Patent: April 4, 2017
    Assignee: The Regents of the University of California
    Inventors: Kathryn M. Kelchner, James S. Speck, Nathan A. Pfaff, Steven P. DenBaars
  • Publication number: 20170077356
    Abstract: A method for fabricating a Zinc Oxide (ZnO) conductive film on a semiconductor material, including depositing a doped ZnO seed layer on a diode, wherein the ZnO seed layer forms an electrical contact to the diode; and depositing a ZnO layer on the ZnO seed layer, wherein the ZnO seed layer and the ZnO layer each have a thickness, a crystal quality, and a doping level such that (1) the diode comprising III-nitride material is turned on with a turn on voltage of 2.75 volts or less applied across the ZnO layers and the diode, and (2) a contact resistance, of a structure comprising the ZnO layers and the diode, is lower as compared to a contact resistance of a structure comprising the ZnO layer directly on the diode without the ZnO seed layer.
    Type: Application
    Filed: September 15, 2016
    Publication date: March 16, 2017
    Applicant: The Regents of the University of California
    Inventors: Asad J. Mughal, Sang Ho Oh, Steven P. DenBaars
  • Patent number: 9574728
    Abstract: A high-power, high-brightness lighting system for large venue lighting, which includes a laser diode as the excitation source and one or more phosphor materials placed at a remote distance from the laser source. The invention offers a lighting system with the advantages of high brightness, high efficiency, high luminous efficacy, long lifetimes, quick turn-on times, suitable color properties, environmental sustainability, and easy maintenance, which may allow for smart and flexible control over large area lighting systems with resulting savings in operating and maintenance costs.
    Type: Grant
    Filed: July 31, 2014
    Date of Patent: February 21, 2017
    Assignee: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Kristin A. Denault, Steven P. DenBaars, Ram Seshadri
  • Patent number: 9515240
    Abstract: A method for increasing the luminous efficacy of a white light emitting diode (WLED), comprising introducing optically functional interfaces between an LED die and a phosphor, and between the phosphor and an outer medium, wherein at least one of the interfaces between the phosphor and the LED die provides a reflectance for light emitted by the phosphor away from the outer medium and a transmittance for light emitted by the LED die. Thus, a WLED may comprise a first material which surrounds an LED die, a phosphor layer, and at least one additional layer or material which is transparent for direct LED emission and reflective for the phosphor emission, placed between the phosphor layer and the first material which surrounds the LED die.
    Type: Grant
    Filed: November 20, 2015
    Date of Patent: December 6, 2016
    Assignee: The Regents of the University of California
    Inventors: Frederic S. Diana, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20160307801
    Abstract: A method for the reuse of gallium nitride (GaN) epitaxial substrates uses band-gap-selective photoelectrochemical (PEC) etching to remove one or more epitaxial layers from bulk or free-standing GaN substrates without damaging the substrate, allowing the substrate to be reused for further growth of additional epitaxial layers. The method facilitates a significant cost reduction in device production by permitting the reuse of expensive bulk or free-standing GaN substrates.
    Type: Application
    Filed: June 22, 2016
    Publication date: October 20, 2016
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Casey O. Holder, Daniel F. Feezell, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20160230312
    Abstract: A nonpolar III-nitride film grown on a miscut angle of a substrate, in order to suppress the surface undulations, is provided. The surface morphology of the film is improved with a miscut angle towards an ?-axis direction comprising a 0.15° or greater miscut angle towards the ?-axis direction and a less than 30° miscut angle towards the ?-axis direction.
    Type: Application
    Filed: April 20, 2016
    Publication date: August 11, 2016
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Asako Hirai, Zhongyuan Jia, Makoto Saito, Hisashi Yamada, Kenji Iso, Steven P. DenBaars, Shuji Nakamura, James S. Speck
  • Patent number: 9396943
    Abstract: A method for the reuse of gallium nitride (GaN) epitaxial substrates uses band-gap-selective photoelectrochemical (PEC) etching to remove one or more epitaxial layers from bulk or free-standing GaN substrates without damaging the substrate, allowing the substrate to be reused for further growth of additional epitaxial layers. The method facilitates a significant cost reduction in device production by permitting the reuse of expensive bulk or free-standing GaN substrates.
    Type: Grant
    Filed: August 28, 2015
    Date of Patent: July 19, 2016
    Assignee: The Regents of the University of California
    Inventors: Casey O. Holder, Daniel F. Feezell, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20160156155
    Abstract: A III-Nitride based Vertical Cavity Surface Emitting Laser (VCSEL), wherein a cavity length of the VCSEL is controlled by etching.
    Type: Application
    Filed: August 6, 2015
    Publication date: June 2, 2016
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Casey O. Holder, Daniel F. Feezell, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Patent number: 9356431
    Abstract: A high power blue-violet Ill-nitride semipolar laser diode (LD) with an output power in excess of 1 W, a slope efficiency of more than 1 W/A, and an external quantum efficiency (EQE) in excess of 25% and more preferably, in excess of 35%. These operating characteristics make these laser diodes suitable for use in solid state lighting systems.
    Type: Grant
    Filed: February 13, 2014
    Date of Patent: May 31, 2016
    Assignee: The Regents of the University of California
    Inventors: Arash Pourhashemi, Robert M. Farrell, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Patent number: 9340899
    Abstract: A nonpolar III-nitride film grown on a miscut angle of a substrate, in order to suppress the surface undulations, is provided. The surface morphology of the film is improved with a miscut angle towards an a-axis direction comprising a 0.15° or greater miscut angle towards the a-axis direction and a less than 30° miscut angle towards the a-axis direction.
    Type: Grant
    Filed: June 16, 2014
    Date of Patent: May 17, 2016
    Assignee: The Regents of the University of California
    Inventors: Asako Hirai, Zhongyuan Jia, Makoto Saito, Hisashi Yamada, Kenji Iso, Steven P. DenBaars, Shuji Nakamura, James S. Speck